2 files changed, 54 insertions, 26 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 4b6423e7bd21..e500f1df1140 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -28,9 +28,11 @@
 
 #include "physaddr.h"
 
-struct ioremap_mem_flags {
-        bool system_ram;
-        bool desc_other;
+/*
+ * Descriptor controlling ioremap() behavior.
+ */
+struct ioremap_desc {
+        unsigned int flags;
 };
 
 /*
@@ -62,13 +64,14 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size,
         return err;
 }
 
-static bool __ioremap_check_ram(struct resource *res)
+/* Does the range (or a subset of) contain normal RAM? */
+static unsigned int __ioremap_check_ram(struct resource *res)
 {
         unsigned long start_pfn, stop_pfn;
         unsigned long i;
 
         if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM)
-                return false;
+                return 0;
 
         start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
         stop_pfn = (res->end + 1) >> PAGE_SHIFT;
@@ -76,28 +79,44 @@ static bool __ioremap_check_ram(struct resource *res)
                 for (i = 0; i < (stop_pfn - start_pfn); ++i)
                         if (pfn_valid(start_pfn + i) &&
                             !PageReserved(pfn_to_page(start_pfn + i)))
-                                return true;
+                                return IORES_MAP_SYSTEM_RAM;
         }
 
-        return false;
+        return 0;
 }
 
-static int __ioremap_check_desc_other(struct resource *res)
+/*
+ * In a SEV guest, NONE and RESERVED should not be mapped encrypted because
+ * there the whole memory is already encrypted.
+ */
+static unsigned int __ioremap_check_encrypted(struct resource *res)
 {
-        return (res->desc != IORES_DESC_NONE);
+        if (!sev_active())
+                return 0;
+
+        switch (res->desc) {
+        case IORES_DESC_NONE:
+        case IORES_DESC_RESERVED:
+                break;
+        default:
+                return IORES_MAP_ENCRYPTED;
+        }
+
+        return 0;
 }
 
-static int __ioremap_res_check(struct resource *res, void *arg)
+static int __ioremap_collect_map_flags(struct resource *res, void *arg)
 {
-        struct ioremap_mem_flags *flags = arg;
+        struct ioremap_desc *desc = arg;
 
-        if (!flags->system_ram)
-                flags->system_ram = __ioremap_check_ram(res);
+        if (!(desc->flags & IORES_MAP_SYSTEM_RAM))
+                desc->flags |= __ioremap_check_ram(res);
 
-        if (!flags->desc_other)
-                flags->desc_other = __ioremap_check_desc_other(res);
+        if (!(desc->flags & IORES_MAP_ENCRYPTED))
+                desc->flags |= __ioremap_check_encrypted(res);
 
-        return flags->system_ram && flags->desc_other;
+        return ((desc->flags & (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)) ==
+                               (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED));
 }
 
 /*
@@ -106,15 +125,15 @@ static int __ioremap_res_check(struct resource *res, void *arg)
  * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES).
  */
 static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
-                                struct ioremap_mem_flags *flags)
+                                struct ioremap_desc *desc)
 {
         u64 start, end;
 
         start = (u64)addr;
         end = start + size - 1;
-        memset(flags, 0, sizeof(*flags));
+        memset(desc, 0, sizeof(struct ioremap_desc));
 
-        walk_mem_res(start, end, flags, __ioremap_res_check);
+        walk_mem_res(start, end, desc, __ioremap_collect_map_flags);
 }
 
 /*
@@ -131,15 +150,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
  * have to convert them into an offset in a page-aligned mapping, but the
  * caller shouldn't need to know that small detail.
  */
-static void __iomem *__ioremap_caller(resource_size_t phys_addr,
-                unsigned long size, enum page_cache_mode pcm,
-                void *caller, bool encrypted)
+static void __iomem *
+__ioremap_caller(resource_size_t phys_addr, unsigned long size,
+                 enum page_cache_mode pcm, void *caller, bool encrypted)
 {
         unsigned long offset, vaddr;
         resource_size_t last_addr;
         const resource_size_t unaligned_phys_addr = phys_addr;
         const unsigned long unaligned_size = size;
-        struct ioremap_mem_flags mem_flags;
+        struct ioremap_desc io_desc;
         struct vm_struct *area;
         enum page_cache_mode new_pcm;
         pgprot_t prot;
@@ -158,12 +177,12 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
                 return NULL;
         }
 
-        __ioremap_check_mem(phys_addr, size, &mem_flags);
+        __ioremap_check_mem(phys_addr, size, &io_desc);
 
         /*
          * Don't allow anybody to remap normal RAM that we're using..
          */
-        if (mem_flags.system_ram) {
+        if (io_desc.flags & IORES_MAP_SYSTEM_RAM) {
                 WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
                           &phys_addr, &last_addr);
                 return NULL;
@@ -201,7 +220,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
          * resulting mapping.
          */
         prot = PAGE_KERNEL_IO;
-        if ((sev_active() && mem_flags.desc_other) || encrypted)
+        if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted)
                 prot = pgprot_encrypted(prot);
 
         switch (pcm) {
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 6ed59de48bd5..5db386cfc2d4 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -12,6 +12,7 @@
 #ifndef __ASSEMBLY__
 #include <linux/compiler.h>
 #include <linux/types.h>
+#include <linux/bits.h>
 /*
  * Resources are tree-like, allowing
  * nesting etc..
@@ -136,6 +137,14 @@ enum {
         IORES_DESC_RESERVED                     = 8,
 };
 
+/*
+ * Flags controlling ioremap() behavior.
+ */
+enum {
+        IORES_MAP_SYSTEM_RAM            = BIT(0),
+        IORES_MAP_ENCRYPTED             = BIT(1),
+};
+
 /* helpers to define resources */
 #define DEFINE_RES_NAMED(_start, _size, _name, _flags)                  \
         {                                                               \